Coal hydrogenation process



Nov. 17, 1959 Filed Nov. 30, 1954 2 Sheets-Sheet 1 f R 9 Hxm2 1 t o Z3 COOLER Hydrogen 20 Gases Gases Hydrogen AND "'1 and iiases Pagfiing CONDENSER L. cow //7 Pasfing Oll I Cafal sf {5 .p L|48 I3 Liquids and Solids' Lig f Liquids Light 7 C l l MIXER Pasfing gg HOT on.

Q AGITATEDJ Producr SEPARQTORg/ and SOIIdS snug Middle Coal /5 Heavy Liqqids l ,2 Km 24 and OlldS I 65 COAL COAL I COAL: 5OLID$ Heavy PlTCH HEATER PULVERIZER BIN SEPAi'iATOR Liquids sriu. Solids Pitch COAL REACTION RATE 7 g 1000 o m 900 f 2 800 With .025 Pound of g.) 3 700 Hydrogen Per Pound o g of CO3 x Lu 0: I M 2 Q 500 I! 2 {j w 4 400 Li 2 O u.

0 8 Whh .035 Pound of 8 o Hydrogen Per Pound g 2 of Coal O 3 8 U o n.

VENTORS EDWARD W. DOUGHTY JOHN PAUL H. HOWELL.JR. 1.. ALSPAUGYH ATTORNEY NOV- 17, 1959 H W AL 2,913,388

JOHN H. HOWELL JR. PAUL L. ALSPAUGH HOT 2 t e e L w m A m 8 0 AR C RT F 2 w mm w 6 U T m k w m I w R I I W a H m .l 0 m Y N D m U a m W 4 o F G O R m m m m a M n F m II N O X I m 0| 0 M/U. s E .T D md N M U v m .m 4 I m 0 5 O 5 O 5 O 0 q 4 3 3 v .2 1 1 M 3 Qu mO zmu mum him-m3 m v 7 mm d W0 .m C H 4 T \iik r kl.

- PRODUCTS ATTORNEY CATALYST U d S ew Pate 2,913,388 COAL HYDROGENATION PRQCESS John H. Howell, Charlestomand Edward W. Doughty and Paul L. Alspaugh, South Charleston, W. Va.

Application November 30, 1954, Serial No. 472,016

18 Claims. (Cl. 208-8) This invention relates to a new and improved process for the hydrogenation-of coal.- More particularly the invention relates to a high temperature, moderate pressure, coal hydrogenation process employing a relatively low volume of reaction space, whereby chemicals in the form of oils, gases and pitch are recovered from the coal in good yields. .1 A

An ample supply of hydrocarbon gases, liquids and pitch and the chemicals derived from or allied to these hydrocarbons is vital to the economy of theUnited States and of the world. Such materials are obtained'from natural gas, petroleum, oil shale, tar sand, lignite or coal.

For more than one hundred years coal has been used to produce gas in the United States by destructive distillation and by other gasification processes resulting in the manufactured gas products thathave been available for general use. And for more than fifty years many of the coke ovens that produce metallurgical coke or coke for other industrial or domestic use from coal have been equipped to separate and recover the volatile products from coal that are higher in density. and molecular Weight than the coke oven gas. Typical of these products are benzol, naphthalene, tar acids, tar bases, creosote oil, road tar andpitch. 1 i

The continuing growth of the chemical industry and the general industrial expansion of the world has created a need for chemicals of these types which is greater than the present and the anticipated future supply from-byproduct coke ovens. :This demand creates an additional drain on the petroleum reserves of the nation and the production of some of these chemicals, from petroleum, such as the tar acids and bases, is very costly.

The United States possesses'vast mineral reserves of bituminous coal. The chemicals presently recovered as byproducts from coke ovens represent only a small fraction, both in number and in variety, of the chemicals actually present in the coal. In recent years plants have been constructed, principally in other countries, for the 2,913,388 Patented Nov. 17, 1959 'ice cals produced as byproducts from coke ovens and from petroleum sources.

The known processes for hydrogenating coal to liquid fuels and chemicals-containing materials have a number of disadvantages. Prominent among these is a low rate of coal hydrogenation which necessitates a large reactor volume. Also undesirable are extremely high pressures in the conversion system and the consumption of large quantities of hydrogen. In these known processes the .coal flow rate varies from 20 to 40 pounds of coal per cubic foot of high pressure converter volume per hour, at an operating temperature of 485 C. or lower, and with a hydrogen consumption of about 0.0825 pound of hydrogen per pound of coal. As will be seen below the process of the present invention achieves a much higher rate of coal hydrogenagion at much lower pressure, with higher temperatures and with lower hydrogen consumption. a a

In the drawings: I a

Figure 1 is a flow sheet for the over-all coal hydrogenation process. a

Figure 2 is a graph showing the efiect of temperature on the coal reaction rate for two different rates of hydrogen consumed per pound of coal.

Figure 3 is a graph showing yields of various types of product plotted against the pounds of hydrogen consumed per pound of coal.

Figure 4 is a drawing of a tubular reactor for hydrogenation.

The flow sheet of Fig. 1 illustrates schematically the progress of the coal through the hydrogenation process and the products that result thereby. The coal as mined, is fed from a storage bin 10 into a pulverizer 11 Where it is first crushed and dried in a hot gas stream until it is substantially free from water. It is then pulverized to a fine state, at least smaller than 10 mesh, U.S. sieve series. The pulverized coal is next introduced into a coal heater 12 where it is heated to a temperature between 350 and 375 C. This heating may be accomplished by indirect heat exchange through metal tubes or preferably by direct contact with a heated inert gas atmosphere as outlined in U.S. patent application Ser. No. 256,301, filed December 14, 1951, now abandoned, and assigned to the same assignee as this application.

From the coal heater 12 the heated pulverized coal goes to a mixer 13 where it is mixedwith hot pasting oil, described later. This hot mixing with the pasting oil is described in U.S. patent application Ser. No. 256,300, filed December 14, 1951, now Patent No. 2,832,724, and assigned to the same assignee as the present application. The preferred concentration of coal in the 'coal in pasting oil mixture is between 40 and percent by weight of coal. From the mixer 13 the mixture of coal in pasting oil is pressurized by a pump 14 and pumped'into a reactor 15. Alternatively to the last mentioned procecoal 1 dures above, the pulverized coal coming from the pulverizer 11 may be mixed unheated with pasting oil and the mixture then heated before introduction into the reactor 15; As will be seen below, however, the procedure shown in thefiow sheet is considered to be preferable.

An alternative procedure is also presented just before the coal in pasting oil mixture is introduced into the reactor 15. At this point a suitable catalyst, as described below, may be introduced if desired. In the reactor 15 the actual hydrogenation of the coal takes place. Hydrogen is introduced and contacted with the coal in oil paste mixture in the reactor vessel 15, which vessel may be one of several types, as will be seen. A minimum pressure of 2,500 pounds per square inch gauge being necessary for the hydrogenation process of the invention, the pump 14 compresses the hot mixture of coal in pasting oil to a moderately high pressure of from 2,500 to 12,000 pounds per square inch gauge, preferably about 4,000 to 6,000 pounds per square inch gauge, before it is admitted to the reactor 15. The hydrogen enters under similar pressure. Temperature within the reactor is maintained at at least 490 C. and preferably between 500 and 560 C.

After leaving the reactor 15, the products are separated in one of several ways. One alternative is to employ a hot separator 16 which separates the reaction product into a vapor stream and a liquid and solids stream. The vapor stream from the hot separator 16 goes to a cold separator 17 where the light liquid vapors are condensed and then out through a pressure reducing pump 18 before passing into light oil stills 19. The uncondensable gases are separated out in the cold separator 17 and are treated in one of several alternative ways. If this gas stream is composed predominantly of hydrogen, it may be scrubbed at the pressure at which it is produced, further pressurized, and then recycled to the reactor 15 for further coal hydrogenation. Or the gas stream may be depressurized by a pump 20 and removed as product. As yet another alternative the gas stream may be put through a high pressure scrubber, not shown on the flow sheet, and the hydrogen separated from the hydrocarbon gases and recycled while the hydrocarbon gases thus separated are depressurized and removed as product. The particular treatment of the gas stream used will depend primarily on the hydrogen content of the gas stream and this is determined in large measure by the type of reactor 15 used. If an agitated reactor is employed the hydrogen content will be relatively high and recycling will be desirable. If, on the other hand, a tubular converter is used nearly all of the hydrogen supplied to the reactor 15 will be used up in the hydrogenation process and the hydrogen content of the gas stream will be quite low so that recycling will be unnecessary and all of the gas streams may be removed as product. The other stream from the hot separator 16, comprising liquids and solids, is put through a pressure reducing pump 21 and then conducted to the light oil stills 19, as is the light liquid stream from the cold separator 17.

An alternative method of preliminary separation can be applied to the products leaving the reactor 15. In this alternative method the products go through a pressure reduction pump 22 and then into a cooler and condenser 23. After cooling the products go to the cold separator 17 from which gases are removed directly as final product, it being unnecessary to use the pressure reduction pump 20 in this case as the gases have already been depressurized by the pump 22. The liquid and solid products, after removal of the gases in the cold separator 17, go directly to the light oil stills 19, the pump 18 being by-passed. The light oil stills 19 thus contain the same liquid and solid products they would if first alternative were followed and the hot separator 16 used.

The light oil stills 19 by distillation yield two final products directly. One is called light oil and contains the majority of the chemical compounds recovered from the coal. This light oil has a boiling point temperature range between 75 and 270 C. at atmospheric pressure. The other final product from the light oil stills 19 is a heavier oil fraction called middle oil which contains other valuable chemicals as will be seen. This middle oil has a boiling point temperature range between 270 and 330 C. at atmospheric pressure.

The light oil stills 19 yield yet another stream comprising heavy liquids, i.e. those boiling above 330 C. at atmospheric pressure, and solids. This stream is conducted into the solids separator 24, which may consist of a centrifuge or a mechanical pressure filter or similar device. The solid residue recovered from the solids separator 24 is a final product of the process and may be used as a fuel if the carbon content is sufliciently high or it may be processed as the ash from steam plants is handled. Heavy liquids from which the solid residue has been removed by the solids separator 24 are introduced into the pitch still 25. In this still the heavier oils in a specific range, called pasting oil, are distilled olf and the remainder is removed as pitch product. The still 25 is of the vacuum type and the pasting oil may be defined as the oils boiling between 330 C. at atmospheric pressure and 350 C. at 5 to 50 mm. of mercury, with the material boiling higher being classed as pitch. This pasting oil fraction is preferably not removed directly as a final product but recycled to the mixer 13 to be mixed with pulverized coal for use in the process. The pitch obtained may be used to manufacture high quality coke suitable for electrode making and similar uses. If desired, a portion of the heavy liquid from the separator 19 may be used directly in admixture with the distilled pasting oil for recycle to the mixer 13.

The coal preferred for use in the process of the invention is of the bituminous type. Also useful, is lignite, as well as tars made from coal or lignite by carbonizetion processes.

The oil used as pasting oil in the process is preferably oil produced in the process itself, that is, solids-free oil, tar or pitch having an initial boiling point temperature above 325 C. at atmospheric pressure. When the pasting oil used is product taken directly from the pitch still 25, there is the added advantage that the oil is already heated and can be introduced directly into the mixer 13 with little or no additional heating. The coal can be preheated before mixing with the pasting oil and the pasting oil likewise heated before mixing or the mixture can be heated after mixing at room temperature. However, in the temperature range between 200 and 370 C. high concentration coal pastes present difliculties in handling. Thus, it is sometimes desirable to preheat the components before mixing because preheating the coal and mixing it with hot pasting oil is a practical method of handling coal pastes having high concentrations of coal. The concentration of coal in the oil paste may be from about 10 to about percent coal by weight. As a matter of process economy and for the best yield of chemicals from coal, a high concentration of coal is most desirable. However, because of the difiiculties of pumping high concentrations of coal up to the pressures used for hydrogenation, mixtures containing more than 80 percent by weight of coal are not considered practical. A concentration of 40 to 70 percent coal by weight in the mixture is preferred.

The addition of a catalyst to the coal in pasting oil mixture before introducing it into the hydrogenation reactor 15 is optional. The use of a suitable catalyst, however, will increase the rate of reaction and lower the required temperature. Suitable catalysts include tin, iron, lead and derivatives of these metals which can be handled as fluids in slurries or solutions with hydrocarbon oils. A nickel catalyst for this purpose is disclosed in US. patent application Serial No. 331,332, filed January 14, 1953, now abandoned, and assigned to the same assignee as this application.

When the heated and pressurized coal in pasting oil mixture is fed intothe reactor together with hot pressurized hydrogen gas, the actual coal hydrogenation reaction occurs. One of the advantages of the process when it is so operated as to produce some pitch from the coal is the utilization of part of the hydrogen contained in the coal to produce gases and oil containing higher percentages of hydrogen than does the coal itself, which at the same time results in pitch low in hydrogen content. When an agitated reactor is used the gas mixture from the cold separator 17 contains as much as 75 percent hydrogen and may be recycled directly as the mixture, or preferably high pressure scrubbing may be employed to separate out the hydrocarbon gases and recycle relatively pure hydrogen to the reactor 15.

The rate of reaction and the ratios of types of products derived from the coal are dependent upon the interrelated factors of temperature, degree of agitation, pressure and ratio of hydrogen added. The reactor must be such as to provide intimate mixing of the liquid, solid and gas phases equivalent to a turbulent flow as typified by an average linear velocity of the gas and liquid phases of from 3 to feet per second or more. A pressure of at least 2,500 pounds per square inch gauge and a temperature above 490 C. are essential for the hydrogenation process of the invention. The hydrogen may be added at a rate of between 1 and 7 pounds of hydrogen per hundred pounds of coal, with from 2.5 to 7 pounds being preferred.

Among the major disadvantages of the prior processes are the low rates of 'coal processing, the high pressures necessary and the large amounts of hydrogen consumed. In the process of our invention, however, these disadvantages have been overcome by the use of the improved reactor vessels described later which permit the use of lower pressures and higher temperatures. Prior processes employed temperatures of 485 C. or lower.

Investigation has shown that when coal is hydrogenated at a temperature in excess of 490 C., the reaction rate to hydrocarbon gas doubles with every degrees centigrade increase in temperature. The reaction rate of coal to liquid products increases also, though at a somewhat lower rate. The effect oftemperature on the hydrogenation reaction rate is shown graphically in Fig. 2, where the quantity of coal hydrogenated per hour per cubic foot of reactor space has been plotted against the temperature, with data given for two dilferent ratios of hydrogen added. From this graph may be readily seen the sharp increase in reaction rate as the temperature is increased. A minimum of 150 pounds of coal reacted per cubic foot of reaction volume per houris desirable for efficient operation, with 200 pounds or more preferred for economic reasons.

The process of the invention has been operated with yields of more than 85 percent conversion of the coal to gaseous and liquid products, using quantities of hydrogen well below the 0.0825 pound of hydrogen per pound of coal average of the prior art. The actual ratios between the three main types of total product, that is gases, oils and pitch is determined by the quantity of hydrogen added per unit quantity of coal. Generally speaking, with conditions of temperature and pressure adjusted properly, the more hydrogen that is added the greater the degree of hydrogenation and hence the larger the proportion of the coal which is converted to gas and liquids and the less to pitch. This is illustrated by Fig. 3 where the percentages of the three types of product obtained from a sample of coal using varying amounts of hydrogen are shown.

A suitable reactor is very important to the successful operation of the invention. Such a reactor or converter is a high pressure, high temperature vessel arranged to provide intimate mixing of the liquid, solid and gas phases, efficient heat transfer for either heating or cooling of the reaction mixture, sufficient volume to provide a reaction time of from one to ten minutes and provision for continuous flow of reactants through the vessel. One such reactor is described in US. patent application Serial No. 350,674, filed April 23,; 1953, now Patent No. 2,766,391, and assigned to the same assignee as this application. This reactor employs mechanical agitation to achieve the necessary intimate admixture of the component phases.

Fig. 4 of the drawing illustrates a preferred type of reactor vessel suitable for the practice of the invention. This reactor is of the tubular type and comprises a plurality of vertical tubes 31 and 35, connected by return bends 33. The mixture of coal in pasting oil, hydrogen and catalyst, if any, flows into the reactor and up through an upward tube 31, through a return bend 33 and downward through a downward tube 35. A return bend 33 then conducts the mixture to another upward tube 31 and the mixture continues in an alternating upward and downward flow through the balance of the reactor tubes. Both upward and downward tubes 31 and 35 have corresponding heating jackets 32 and 34.

These heating jackets surround the lengths of the reaction tubes and are equipped with suitable connections for circulating heat exchange fluid through the annular space between the jacket and the tube. The jackets can be. used to either heat or cool the contents of the tube. The heating jackets provide a very sensitive and accurate means for controlling the temperature of the reactants within the tube. This reactor has the additional advantage that temperature can be varied at different points in the reaction process by simply varying the temperature of the heating fluid in different sections of the heating jackets.

The high temperatures employed in the process of the invention make it possible to putthe mixture through the second or more may be used. The high velocity and rate of reaction result in a very high reaction rate per cubic foot of reactor, an important economic consideration. As has been pointed out in describing the process, the tubular reactor has the further advantage of very eflicient consumption of hydrogen, which makes recycling of the hydrogen content of the product gases unnecessary, thereby etfecting further economy of operation. 7

A distinct advantage of the tubular reactor is the lack of necessity for any moving parts to insure agitation. Merely forcing the reactants through the tubes at high velocities insures adequate mixing. In the upward tube 31 the gas phase bubbles upward through the liquid phase and intimate admixture is assured. In the downward pipes however there is a tendency for the liquid phase to form a film on the walls of the tubes with the other phases passing through the middle. To minimize this occurrence and further good mixing the downward tubes 35 are made from 25 to 75 percent smaller in diameter than the upward tubes 31, thus constricting the reactants and substantially preventing separation of the phases.

Fig. 4 of the drawing as discussed above illustrates the preferred form of the invention wherein the tubes are in a vertical position. There are several advantages to this, including good space utilization and more thorough mixing of the phases at lower velocities with the constant reversals of direction and the constricted downward tubes. However, tubes inclined at a lesser angle than 90 with the horizontal or even horizontal tubes can be used, provided the velocity of the reactants through the tube is kept high enough to insure turbulence and thorough mixing of the phases, 8 feet per second being the desirable minimum for non-vertical tubes and velocities as high as feet per second may be used in these tubes. With horizontal tubing of course all tube diameters would be the same.

The advantages of the coal hydrogenation process of the invention are clearly illustrated in Table I, a table of operating conditions wherein the process of the invention is compared to the twomajor prior processes. 'i

TABLE I Comparison of process operating conditions for coal hydrogenation Process of the Prior Art Prior Art Operating Invention Process A 1 Process B 2 Conditions Min. Max. Min. Max. Min. Max.

Pressure in lbs/sq.

in 2,000 10,000 3, 000 10,000 7,500 10,000 Temperature in C. 400 560 450 480 445 470 Type oi Reactor Agitagedv pot or For Pot Velocity of Reacting Mixture in Ila/sec 3.5 20

Hydrogen consumption in lbs/lb. of coal 01 .08 .05 12 04 11 Reaction Time in Minutes 1. 15 B0 Coal rate through the reactor, 1bs./ Inn/cu. it. of reactor volume..-" 150 1, 000 20 '10 24 20 Goal Paste Concentration, percent coal in paste 40 30 50 30 45 1 "High Pressure Hydrogenation at Ludwigshafcn-Heidelberg," ATI No. 76,480, August 1050, Central Air Document-s Office.

2 United States Department of the Interior, Bureau of Mines, Report of Investigations 5,043," April 1954.

By the process of the invention a wide variety of valuable chemicals are ultimately produced. Analysis of the products from various runs of the process of the invention has demonstrated that when the process is operated with the preferred operating conditions given earlier, the gas, oil and pitch products obtained will have certain characteristics of chemical composition. For example, it has been found that by the process of the invention at least 10 percent by weight of the coal is converted to a light oil fraction having a boiling point temperature range between and 300 C. at atmospheric pressure, and that this fraction comprises at least 20 percent by weight of phenolic materials and at least 4 percent by weight of nitrogen containing organic compounds, with the balance predominantly aromatic hydrocarbons. Further, it has been found that in the light oil fraction the phenols present which boil at a temperature between 230 and 270 C. contain from 15 to 30 percent by weight of indanols and the final yield of indanols is from 0.1 to 0.3 percent of the weight of coal processed and at least 0.2 pound of indanols per cubic foot of reactor volume per hour. It has also been found that these phenols boiling between 230 and 270 C. have at least 70 percent of the ortho and para position unsubstituted except by hydrogen.

The phenols as a whole represent at least 4 percent by weight of the coal processed, the yield of phenols being at least 8 pounds of phenols per cubic foot of reactor volume per hour. From 40 to 50 percent by weight of the phenols boiling at temperatures between 207 and 230 C. are ethyl substituted phenols.

It has been further noted that in the light oil produccd by the process of invention at least 2 percent by weight of the mononuclear nitrogen bases present are heterocyclic tertiary amino type compounds. Also, indoles constitute at least 0.1 percent of the total weight of coal processed and the yield of indolcs is at least 0.2 pound per cubic foot of reactor volume per hour. From 50 to percent by weight of the hydrocarbons present in the light oil product are aromatic in nature andat least 10 percent are naphthalencs.

The process of the invention was operated for one month in the manner shown in Fig. 1 of the drawing, using a tubular reactor. Average operating conditions and yields for this period are shown below.

8 Operating conditions: Type of coal: Pittsburgh Number 8 Seam Coal. Reactor pressure, pounds per square inch gauge 4500' Reactor maximum temperature, degrees C 510 Coal rate through the reactor, pounds per hour per cubic foot of reactor volume 150 Coal paste concentration, percent coal 50 Hydrogen feed rate, thousand standard cubic feet per hour 70 Hydrogen feed, pounds per pounds coal 4.0 Velocity of reacting mixture, feet per second- 10 Ash free benzene insolublcs, pounds per 100 pounds coal 29 Ash free pyridine insolubles, pounds per 100 pounds coal 7 Hydrogen reacted, pounds per 100 pounds of coal 3.0

Raw product yield (pounds per 100 pounds of coal):

Raw light oil 16.2 Raw middle oil 7.1 Gas 13.8 Pitch 30.0

Refined product yield (pounds per 100 pounds of coal):

Phenol 80-20 (80 percent phenol and 20 High boiling hydrocarbons, 230-260 C 2.06 High boiling hydrocarbons, above 260 C 3.48

Total neutral light oil 10.44

We claim:

1. A process for producing hydrogenation products from coal, characterized in that at least 10 percent by Weight of the coal is converted to a light oil fraction having a boiling temperature range between 75 and 300 C. at atmospheric pressure, said light oil fraction comprising at least 20 percent by weight of phenolic materials, at least 4 percent by weight of nitrogen-containing organic compounds, and the balance predominantly aromatic hydrocarbons; which process comprises mixing pulverized coal with a pasting oil to form a coal paste containing at least 40 percent by weight of coal, forming a multi-phasc mixture of said coal paste as a liquid phase with hydrogen as a gas phase at a pressure of at least 2500 pounds per square inch gauge, heating said multi-phase mixture to a reaction temperature of at least 500 C. and causing intimate intermingling of said gas and liquid phases to permit a reaction rate of at least pounds of coal reacted per cubic foot of reaction volume per hour, and in said reaction forming coal hydrogenation products in which from about 0.01 to about 0.07 pound of hydrogen have combined with each pound of coal introduced.

2. A process for producing hydrogenation productsfrom coal, characterized in that at least '10'percent by weight of the coal is converted to a light oil fraction having a boiling temperature range between 75 and 300 C. at atmospheric pressure, said light oil fraction comprising at least 20 percent by weight of phenolic materials, at least 4 percent by weight of nitrogen-containing organic compounds, and the balance predominantly aromatic hydrocarbons; which process comprises mixing pulverized coal with a pasting oil to form a coal paste containing at least 40 percent by weight of coal, forming a multi-phase mixture of said coal paste as a liquid phase with hydrogen as a gas phase at a pressure of at least 2500 pounds per square inch gauge, heating said multi-phase mixture to a reaction temperature between 500 and 600 C. and causing intimate intermingling of said gas and liquid phases to permit a reaction rate of at least 150 pounds of coal reacted per cubic foot of reaction volume per hour, and in said reaction vforming coal hydrogenation products in which from about 0.01 to about 0.07 pound of hydrogen have combined with each pound of coal introduced.

3. A process for producing hydrogenation products from coal, characterized in that at least percent by weight of the coal is converted to a light oil fraction having a boiling temperature range between 75 and 300 C. at atmospheric pressure, said light oil fraction comprising at least 20 percent by weight of phenolic materials, at least 4 percent by weight of nitrogen-containing organic compounds, and the balance predominantly aromatic hydrocarbons; which process comprises mixing pulverized coal with a pasting oil to form a coal paste containing at least 40 percent by weight of coal, forming a multi-phase mixture of said coal paste as a liquid phase with hydrogen as a gas phase at a pressure of at least 2500 pounds per square inch gauge, heating said multiphase mixture to a reaction temperature between 500 and 560 C. and causing intimate intermingling of said gas and liquid phases to permit a reaction rate of at least 150 pounds of coal reacted per cubic foot of reaction volume per hour, and in said reaction forming coal hydrogenation products in which from 0.01 to about 0.07 pound of hydrogen have combined with each pound of coal introduced.

4. A process for producing hydrogenation products from coal, characterized in that at least 10 percent by weight of the coal is converted to a light oil fraction having a boiling temperature range between 75 and 300 C. at atmospheric pressure, said light oil fraction comprising at least 20 percent by weight of phenolic materials, at least 4 percent by weight of nitrogen-containing organic compounds, and the balance predominantly aromatic hydrocarbons; which process comprises mixing pulverized coal with a pasting oil to form a coal paste containing at least 40 percent by weight of coal, forming a multiphase mixture of said coal paste as a liquid phase with hydrogen as a gas phase at a pressure between 2500 and 12,000 pounds per square inch gauge, heating said multiphase mixture to a reaction temperature of at least 500 C. and causing intimate intermingling of said gas and liquid phases to permit a reaction rate of at least 200 pounds of coal reacted per cubic foot of reaction volume per hour, and in said reaction forming coal hydrogenation products in which from about 0.01 to about 0.07 pound of hydrogen have combined with each pound of coal introduced.

5. A process for producing hydrogenation products from coal, characterized in that at least 10 percent by weight of the coal is converted to a light oil fraction having a boiling temperature range between 75 and 300 C. at atmospheric pressure, said light oil fraction comprising at least 20 percent by weight of phenolic materials, at least 4 percent by weight of nitrogen-containing organic compounds, and the balance predominantly aromatic hydrocarbons; which process comprises mixing pulverized coal with a pasting oil to form a coal paste containing at least 40 percent by weight of-coal, forming a multi-phase mixture of said coal paste as a liquid phase with hydrogen as a gas phase at a pressure 'of about 4000 to 6000 pounds per square inch gauge, heating said multi-phase mixture to a reaction temperature of at least 500 C. and causing intimate intermingling of said gas and liquid phases to permit a reaction rate of at least 150 pounds of coal reacted per cubic foot of reaction volume per hour, and in said reaction forming coal hydrogenation products in which from about 0.01 to about 0.07 pound of hydrogen have combined with each pound of coal introduced.

6. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that indanols comprise from 15 to 30 percent by weight of the phenols boiling at temperatures between 230 and 270 C. in said fraction and the yield of indanols is from 0.1 to 0.3 percent of the weight of coal processed and at least 0.2 pound of indanols per cubic foot of reactor volume per hour.

7. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that the phenols boiling at temperatures between 230 and 270 C. in said fraction have at least 70 percent of the ortho and para positions unsubstituted.

8. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that from 40 to 50 percent by weight of the phenols boiling at temperatures between 207 and 230 C. in said fraction are ethyl substituted phenols.

9. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that it contains phenols in the amount of at least 4 percent of the weight of coal processed and at least 8 pounds of phenols per cubic foot of reactor volume per hour.

10. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that at least 2 percent by weight of the mononuclear nitrogen bases in said fraction are heterocyclic tertiary amino type compounds.

11. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that it contains indoles in the amount of at least 0.1 percent of the weight of coal processed and at least 0.2 pound of indoles per cubic foot of reactor volume per hour.

12. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that the hydrocarbons in said fraction consist of at least 10 percent by weight of naphthalenes.

13. A light oil coal hydrogenation fraction made by a process according to claim 1, said fraction being characterized in that between 50 and percent by weight of the hydrocarbons in said fraction are aromatic in nature.

14. A process according to claim 1, said process being further characterized in that the intimate intermingling of said gas and liquid phases during the hydrogenation reaction is accomplished in a tubular reactor comprising a plurality of tubes, said gas and liquid phases being .caused to flow through said tubes with an average velocity of at least 3.5 feet per second, and said tubes being equipped with means for heating and cooling said tubes. 15. A process according to claim 1, said process being further characterized in that the intimate intermingling of said gas and liquid phases during the hydrogenation reaction is accomplished in a tubular reactor comprising a plurality of horizontal tubes, said gas and liquid phases being caused to flow through said tubes with an average velocity of at least 8 feet per second, and said tubes being equipped with means for heating and cooling said tubes.

16. A process according to claim 1, said process being further characterized in that the intimate intermingling of said gas and liquid phases during the hydrogenation reaction is accomplished in a tubular reactor comprising a pluralityof vertical tubes, said gas and liquid phases being caused to flow through said tubes with an average velocity of at least 3.5 feet per second, said tubes being so connected that said gas and liquid phases while passing through said tubes are caused to flow alternately in an upward and then in a downward direction through said tubes, and said tubes being equipped with means for heating and cooling said tubes.

17. A process according to claim 16, said process being further characterized in that the portion of said tubes through which said gas and liquid phases flow in a downward direction is between 25 and 75 percent smaller in diameter than the portion of said tubes through which said phases flow in an upward direction.

18. A process according to claim 1, said process being further characterized in that the intimate intermingling of said gas and liquid phases is accomplished in a reactor vessel, said vessel being equipped with means for violent UNITED STATES PATENTS 1,904,477 Krauch et al Apr. 18, 1933 2,106,973 Ellis Feb. 1, 1938 2,377,728 Thomas June 5,1945 2,572,061 Sellers Oct. 23, 1951 2,654,695 Gilbert et a1. Oct. 6, 1953 Frese et a1 Mar. 13, 1956 OTHER REFERENCES Hydrogenation of Organic Substances, Ellis, 3d ed., D. Van Nostrand Co., New York, pages 505, 506- and 548 (1930). 

1. A PROCESS FOR PRODUCING HYDROGENATION PRODUCTS FROM COAL, CHARACTERIZED IN THAT AT LEAST 10 PERCENT BY WEIGHT OF THE COAL IS CONVERTED TO A LIGHT OIL FRACTION HAVING A BOILING TEMPERATURE RANGE BETWEEN 75* AND 300*L TO C. AT ATMOSPHERIC PRESSURE, SAID LIGHT OIL FRACTION COMPRISING AT LEAST 20 PERCENT BY WEIGHT OF PHENOLIC MATERIALS, AT LEAST 4 PERCENT BY WEIGHT OF NITROGEN-CONTAINING ORGANIC COMPOUNDS, AND THE BALANCE PREDOMINANTLY AROMATIC HYDROCARBONS; WHICH PROCESS COMPRISES MIXING PULVERIZEDD A COAL WITH A PASTING OIL TO FORM A COAL PASTE CONTAINING AT LEAST 40 PERCENT BY WEIGHT OF COAL, FORMING A MULTI-PHASE MIXTURE OF SAID COAL PASTE AS A LIQUID PHASE WITH HYDROGEN AS A GAS PHASE AT A PRESSURE OF AT LEAST 2500 POUNDS PERRSQUARE INCH GUAGE HEATING SAID MULTI-PHASE MIXTURE TO A REACTION TEMPERATURE OF AT LEAST 500*C. AND CAUSING INTIMATE INTERMINGLING OF SAID GAS AND LIQUID PHASES TO PERMIT A REACTION RATE OF AT LEAST 150 POUNDS OF COAL REACHED PER CUBIC FOOT OF REACTION VOLUME PER HOUR, AND IN SAID REACTION FORMING COAL HYDROGENATION PRODUCTS IN WHICH FROM ABOUT 0.01 TO ABOUT 0.0M POUND OF HUDROGEN HAVE COMBINED WITH EACH POUND OF COAL INTRODUCED. 